[TOPI, Relay] Support roi_align NHWC layout

python/tvm/relay/op/strategy/cuda.py

@@ -945,12 +945,20 @@ def roi_align_strategy_cuda(attrs, inputs, out_type, target):
     """roi_align cuda strategy"""
     strategy = _op.OpStrategy()
     layout = attrs.layout
-    assert layout == "NCHW", "only support nchw for now"
-    strategy.add_implementation(
-        wrap_compute_roi_align(topi.vision.rcnn.roi_align_nchw),
-        wrap_topi_schedule(topi.cuda.schedule_roi_align),
-        name="roi_align_nchw.cuda",
-    )
+
+    if layout == "NCHW":
+        strategy.add_implementation(
+            wrap_compute_roi_align(topi.vision.rcnn.roi_align_nchw),
+            wrap_topi_schedule(topi.cuda.schedule_roi_align),
+            name="roi_align_nchw.cuda",
+        )
+    else:
+        assert layout == "NHWC", "layout must be NCHW or NHWC."
+        strategy.add_implementation(
+            wrap_compute_roi_align(topi.vision.rcnn.roi_align_nhwc),
+            wrap_topi_schedule(topi.cuda.schedule_roi_align),
+            name="roi_align_nhwc.cuda",
+        )
     return strategy
 
 

python/tvm/relay/op/strategy/generic.py

@@ -1039,7 +1039,6 @@ def wrap_compute_roi_align(topi_compute):
     """wrap roi_align topi compute"""
 
     def _compute_roi_align(attrs, inputs, out_type):
-        assert attrs.layout == "NCHW"
         pooled_size = get_const_tuple(attrs.pooled_size)
         mode = bytes(attrs.mode, "utf-8")
         return [
@@ -1061,12 +1060,19 @@ def roi_align_strategy(attrs, inputs, out_type, target):
     """roi_align generic strategy"""
     strategy = _op.OpStrategy()
     layout = attrs.layout
-    assert layout == "NCHW", "only support nchw for now"
-    strategy.add_implementation(
-        wrap_compute_roi_align(topi.vision.rcnn.roi_align_nchw),
-        wrap_topi_schedule(topi.generic.schedule_roi_align),
-        name="roi_align.generic",
-    )
+    if layout == "NCHW":
+        strategy.add_implementation(
+            wrap_compute_roi_align(topi.vision.rcnn.roi_align_nchw),
+            wrap_topi_schedule(topi.generic.schedule_roi_align),
+            name="roi_align.generic",
+        )
+    else:
+        assert layout == "NHWC", "layout must be NCHW or NHWC."
+        strategy.add_implementation(
+            wrap_compute_roi_align(topi.vision.rcnn.roi_align_nhwc),
+            wrap_topi_schedule(topi.generic.schedule_roi_align),
+            name="roi_align.generic",
+        )
     return strategy
 
 

python/tvm/relay/op/strategy/x86.py

@@ -481,12 +481,19 @@ def roi_align_strategy_cpu(attrs, inputs, out_type, target):
     """roi_align x86 strategy"""
     strategy = _op.OpStrategy()
     layout = attrs.layout
-    assert layout == "NCHW", "only support nchw for now"
-    strategy.add_implementation(
-        wrap_compute_roi_align(topi.x86.roi_align_nchw),
-        wrap_topi_schedule(topi.generic.schedule_roi_align),
-        name="roi_align.x86",
-    )
+    if layout == "NCHW":
+        strategy.add_implementation(
+            wrap_compute_roi_align(topi.x86.roi_align_nchw),
+            wrap_topi_schedule(topi.generic.schedule_roi_align),
+            name="roi_align.x86",
+        )
+    else:
+        assert layout == "NHWC", "layout must be NCHW or NHWC."
+        strategy.add_implementation(
+            wrap_compute_roi_align(topi.vision.rcnn.roi_align_nhwc),
+            wrap_topi_schedule(topi.generic.schedule_roi_align),
+            name="roi_align.x86",
+        )
     return strategy
 
 

python/tvm/relay/op/vision/_vision.py

@@ -86,7 +86,7 @@ def nms_shape_func(attrs, inputs, _):
 
 
 @script
-def _roi_align_shape_func(data_shape, rois_shape, pooled_size):
+def _roi_align_shape_func_nchw(data_shape, rois_shape, pooled_size):
     out = output_tensor((4,), "int64")
     out[0] = rois_shape[0]
     out[1] = data_shape[1]
@@ -95,6 +95,19 @@ def _roi_align_shape_func(data_shape, rois_shape, pooled_size):
     return out
 
 
+@script
+def _roi_align_shape_func_nhwc(data_shape, rois_shape, pooled_size):
+    out = output_tensor((4,), "int64")
+    out[0] = rois_shape[0]
+    out[1] = int64(pooled_size[0])
+    out[2] = int64(pooled_size[1])
+    out[3] = data_shape[3]
+    return out
+
+
 @reg.register_shape_func("vision.roi_align", False)
 def roi_align_shape_func(attrs, inputs, _):
-    return [_roi_align_shape_func(inputs[0], inputs[1], convert(attrs.pooled_size))]
+    if attrs.layout == "NCHW":
+        return [_roi_align_shape_func_nchw(inputs[0], inputs[1], convert(attrs.pooled_size))]
+    assert attrs.layout == "NHWC", "layout must be NCHW or NHWC."
+    return [_roi_align_shape_func_nhwc(inputs[0], inputs[1], convert(attrs.pooled_size))]

python/tvm/topi/testing/__init__.py

@@ -39,7 +39,7 @@
 from .bilinear_resize_python import bilinear_resize_python
 from .trilinear_resize3d_python import trilinear_resize3d_python
 from .reorg_python import reorg_python
-from .roi_align_python import roi_align_nchw_python
+from .roi_align_python import roi_align_nchw_python, roi_align_nhwc_python
 from .roi_pool_python import roi_pool_nchw_python
 from .lrn_python import lrn_python
 from .l2_normalize_python import l2_normalize_python

python/tvm/topi/testing/roi_align_python.py

@@ -20,42 +20,51 @@
 import numpy as np
 
 
-def roi_align_nchw_python(a_np, rois_np, pooled_size, spatial_scale, sample_ratio, mode=b"avg"):
-    """Roi align in python"""
-    avg_mode = mode in (b"avg", "avg", 0)
-    max_mode = mode in (b"max", "max", 1)
-    assert avg_mode or max_mode, "Mode must be average or max. Please pass a valid mode."
-    _, channel, height, width = a_np.shape
-    num_roi = rois_np.shape[0]
-    b_np = np.zeros((num_roi, channel, pooled_size, pooled_size), dtype=a_np.dtype)
-    if isinstance(pooled_size, int):
-        pooled_size_h = pooled_size_w = pooled_size
-    else:
-        pooled_size_h, pooled_size_w = pooled_size
-
-    def _bilinear(n, c, y, x):
-        if y < -1 or y > height or x < -1 or x > width:
-            return 0
+def _bilinear(a_np, n, c, y, x, height, width, layout):
+    if y < -1 or y > height or x < -1 or x > width:
+        return 0
 
-        y = min(max(y, 0), height - 1)
-        x = min(max(x, 0), width - 1)
+    y = min(max(y, 0), height - 1)
+    x = min(max(x, 0), width - 1)
 
-        y_low = int(math.floor(y))
-        x_low = int(math.floor(x))
-        y_high = y_low + 1
-        x_high = x_low + 1
+    y_low = int(math.floor(y))
+    x_low = int(math.floor(x))
+    y_high = y_low + 1
+    x_high = x_low + 1
 
-        wy_h = y - y_low
-        wx_h = x - x_low
-        wy_l = 1 - wy_h
-        wx_l = 1 - wx_h
+    wy_h = y - y_low
+    wx_h = x - x_low
+    wy_l = 1 - wy_h
+    wx_l = 1 - wx_h
 
-        val = 0
-        for wx, xp in zip((wx_l, wx_h), (x_low, x_high)):
-            for wy, yp in zip((wy_l, wy_h), (y_low, y_high)):
-                if 0 <= yp < height and 0 <= xp < width:
+    val = 0
+    for wx, xp in zip((wx_l, wx_h), (x_low, x_high)):
+        for wy, yp in zip((wy_l, wy_h), (y_low, y_high)):
+            if 0 <= yp < height and 0 <= xp < width:
+                if layout == "NCHW":
                     val += wx * wy * a_np[n, c, yp, xp]
-        return val
+                else:
+                    val += wx * wy * a_np[n, yp, xp, c]
+    return val
+
+
+def roi_align_common(
+    a_np,
+    b_np,
+    rois_np,
+    channel,
+    pooled_size_h,
+    pooled_size_w,
+    spatial_scale,
+    sample_ratio,
+    avg_mode,
+    max_mode,
+    height,
+    width,
+    layout,
+):
+    """Common code used by roi align NCHW and NHWC"""
+    num_roi = rois_np.shape[0]
 
     for i in range(num_roi):
         roi = rois_np[i]
@@ -70,8 +79,8 @@ def _bilinear(n, c, y, x):
         if sample_ratio > 0:
             roi_bin_grid_h = roi_bin_grid_w = int(sample_ratio)
         else:
-            roi_bin_grid_h = int(math.ceil(roi_h / pooled_size))
-            roi_bin_grid_w = int(math.ceil(roi_w / pooled_size))
+            roi_bin_grid_h = int(math.ceil(roi_h / pooled_size_h))
+            roi_bin_grid_w = int(math.ceil(roi_w / pooled_size_w))
 
         count = roi_bin_grid_h * roi_bin_grid_w
 
@@ -87,8 +96,80 @@ def _bilinear(n, c, y, x):
                             y = roi_start_h + ph * bin_h + (iy + 0.5) * bin_h / roi_bin_grid_h
                             x = roi_start_w + pw * bin_w + (ix + 0.5) * bin_w / roi_bin_grid_w
                             if avg_mode:
-                                total += _bilinear(batch_index, c, y, x) / count
+                                total += (
+                                    _bilinear(a_np, batch_index, c, y, x, height, width, layout)
+                                    / count
+                                )
                             if max_mode:
-                                total = max(total, _bilinear(batch_index, c, y, x))
-                    b_np[i, c, ph, pw] = total
+                                total = max(
+                                    total,
+                                    _bilinear(a_np, batch_index, c, y, x, height, width, layout),
+                                )
+
+                    if layout == "NCHW":
+                        b_np[i, c, ph, pw] = total
+                    else:
+                        b_np[i, ph, pw, c] = total
     return b_np
+
+
+def roi_align_nchw_python(a_np, rois_np, pooled_size, spatial_scale, sample_ratio, mode=b"avg"):
+    """Roi align NCHW in python"""
+    avg_mode = mode in (b"avg", "avg", 0)
+    max_mode = mode in (b"max", "max", 1)
+    assert avg_mode or max_mode, "Mode must be average or max. Please pass a valid mode."
+    _, channel, height, width = a_np.shape
+    if isinstance(pooled_size, int):
+        pooled_size_h = pooled_size_w = pooled_size
+    else:
+        pooled_size_h, pooled_size_w = pooled_size
+
+    b_np = np.zeros((rois_np.shape[0], channel, pooled_size_h, pooled_size_w), dtype=a_np.dtype)
+
+    return roi_align_common(
+        a_np,
+        b_np,
+        rois_np,
+        channel,
+        pooled_size_h,
+        pooled_size_w,
+        spatial_scale,
+        sample_ratio,
+        avg_mode,
+        max_mode,
+        height,
+        width,
+        "NCHW",
+    )
+
+
+def roi_align_nhwc_python(a_np, rois_np, pooled_size, spatial_scale, sample_ratio, mode=b"avg"):
+    """Roi align NHWC in python"""
+    avg_mode = mode in (b"avg", "avg", 0)
+    max_mode = mode in (b"max", "max", 1)
+    assert avg_mode or max_mode, "Mode must be average or max. Please pass a valid mode."
+    _, height, width, channel = a_np.shape
+    num_roi = rois_np.shape[0]
+
+    if isinstance(pooled_size, int):
+        pooled_size_h = pooled_size_w = pooled_size
+    else:
+        pooled_size_h, pooled_size_w = pooled_size
+
+    b_np = np.zeros((num_roi, pooled_size_h, pooled_size_w, channel), dtype=a_np.dtype)
+
+    return roi_align_common(
+        a_np,
+        b_np,
+        rois_np,
+        channel,
+        pooled_size_h,
+        pooled_size_w,
+        spatial_scale,
+        sample_ratio,
+        avg_mode,
+        max_mode,
+        height,
+        width,
+        "NHWC",
+    )